Mac’s Engineering

Mac’s Engineering CC provides technical and service support to the mining and process industry. The company was initiated in 1987 with a new prototype double deck resonance screen and was registered in 1989 to pursue the manufacture and supply of resonance screening equipment. Operations extend to project management, drawing and design, fabrication, conveyor manufacturing and installation, general engineering and repairs, installation and commissioning of turn key projects, and after sales service. Customer base encompasses the whole commodity market in South Africa, with screens, upgrades, additions and complete plants supplied. The company holds contractor and original equipment vendor numbers for all major companies.

Mac’s Engineering designs and builds double deck resonance screens as well as brute force vibrator screens and feeders. Services include assistance with selection and design of screening equipment for each application, exchange drive units for Mac’s resonance screens, and maintenance service including balancing, changing of working rubbers, rubber bushes and all other screen-related materials and equipment. Quality control systems are in place and Mac’s Engineering is striving towards ISO 9000.

Resonance screens offer true balanced mass design where decks are balanced against each other without non-productive counterweights, resulting in higher capacities with reduced operating costs. Open design permits quick and easy replacement of screen cloth or poly panels with interchangeable screen frames as an option. Live action of screens is never dampened by snubbers, with natural frequency shear-block springs transmitting the entire throw of the positive drive to the decks. Linear oscillation lifts material from screen decks and throws it forward without sliding, so screen cloths last longer and intermediate size particles are dislodged, minimizing blinding and increasing screening efficiency. Resonance screen design eliminates large erratic vibrations during starting and stopping, running smoothly and quietly. They require as little as 30 percent of the power demanded by comparable screens, driven by standard normal starting motors with minimum power consumption once in operation. The exclusive design has screen decks supported at the centre of oscillation, the point of no vibration, so screens transmit no vibration to the base frame or supporting structure, cutting installation and maintenance costs. Standard lengths to 30 feet and widths to 6 feet are offered. A single screen can make up to seven size separations, a job requiring two or more screens of other makes. Shear-block springs do not require maintenance and are not subject to sudden failure as steel springs are, normally good for five years and longer with visual signal of failure for replacement during normal shutdowns. Mac’s screens are shipped complete and do not require special foundation or supporting structure, mountable over bins, on portable rigs or in buildings. Equally effective on wet or dry material and can be equipped with spray bars and other typical screening operation accessories.

Brute force vibrator screens and feeders are purpose designed with flexibility to meet customer special needs, using unbalance vibrator motors to create linear amplitude, Rosta suspensions to control low frequency run-out, robustly built with heavy gauge side plates, G-forces from 3.5 to 4.7g and amplitudes from 6mm to 9mm with low maintenance.